Sea bunnies are a species of sea slug known for their striking resemblance to a fluffy rabbit. Their appearance, characterized by what looks like ears and a tail, has made them a popular subject. These small, shell-less mollusks highlight the diversity and forms found within our oceans.
What Are Sea Bunnies?
Sea bunnies are a type of dorid nudibranch, which are soft-bodied marine gastropod mollusks without a shell in their adult stage. The scientific name for the most commonly recognized “sea bunny” is Jorunna parva. These tiny creatures average around 1 inch (2.54 cm) in length.
The features that give them their rabbit-like appearance are specialized organs. The two prominent “ears” on their head are chemosensory organs called rhinophores. These rhinophores play a crucial role in sensing the marine environment. The “tail” is a cluster of external gills, which are used for respiration. Their seemingly furry texture comes from small rod-like structures called caryophyllidia covering their backs, thought to have sensory functions.
Their Natural Habitat
Sea bunnies are found in the tropical Indo-Pacific Ocean. Their known distribution includes waters around Japan, the Philippines, Indonesia, Australia, Tanzania, Papua New Guinea, and Seychelles. They inhabit coastal areas, preferring environments such as coral reefs and sandy seabeds.
These small slugs are often found in shallow waters, typically up to 20 meters deep, where they cling to submerged vegetation or explore the ocean floor. Sea bunnies predominantly feed on specific types of toxic sponges from the family Chalinidae. They also consume algae and other small sea creatures.
Distinctive Characteristics
The distinctive “ears” of the sea bunny, known as rhinophores, are highly sensitive chemosensory organs. These structures allow the sea bunny to detect chemical scents dissolved in the water, which is how they locate food sources and potential mates from surprising distances. The fuzzy appearance of their rhinophores increases the surface area, enhancing their ability to receive these chemical signals.
The “tail-like” structure at their rear is actually a plume of external gills. These gills are essential for the sea bunny’s respiration, maximizing the surface area for efficient oxygen absorption from the surrounding water. Sea bunnies exhibit varied colorations, including white, yellow, orange, and even brown, often with black spots. This coloration can be influenced by their diet and serves as a warning to predators, as sea bunnies absorb toxins from the sponges they consume. These absorbed toxins make them unpalatable and highly toxic to most potential predators, serving as a defense mechanism.